Integrated surveillance and control

ABSTRACT

A method of managing oilfield activity with a control system is provided having a plurality of virtual sensors and integrating the virtual sensors into a virtual sensor network. The method includes determining interdependencies among the virtual sensors, obtaining operational information from the virtual sensors, and providing virtual sensor output to the control system based on the determined interdependencies and the operational information.

BACKGROUND

In the field of oil and gas exploration, development, and production theability to oversee and manage the various aspects of hydrocarbonproducing fields as a single holistic system has been difficult toachieve. For any asset, there are typically multiple applications,multiple data sets, multiple operational variables and multiplestakeholders involved, some or all of which may be sharing common dataacross the asset. Numerous oilfield activities, such as drilling,evaluating, completing, monitoring, producing, simulating, reporting,etc., may be performed. Typically, each oilfield activity is performedand controlled separately using separate oilfield applications that areeach written for a single purpose. Thus, many such activities are oftenperformed using separate oilfield applications. In some cases, it may benecessary to develop special applications, or modify existingapplications to provide the necessary functionality. Interoperabilityamong these programs, persons, and structures as a single system, whiledesired, has been frustrated by the lack of an underlying framework forhandling the necessary transformations, translations, and definitionsrequired between and among the various system components.

Attempts to provide subsurface understanding as well as efficientoperation have previously focused on providing data replication, whereeach stakeholder group develops or receives its own version of thelogical network and data model that includes all of its requirements. Inthese attempts, the act of transforming the data model by correlatingchanges between the data model representations has not been done or hasbeen done crudely. Although some level of interoperability has beenachieved by point-to-point integration, it is largely limited tosupporting single workflows. Moreover, changes to the data modelrepresentations cannot be effectively controlled when each stakeholdercan decide whether such changes should be applied (accepted) andcommunicated to the other stakeholders. Previous approaches thus, havebeen unable to account for reconciliation and data integrity issues in asystematic and/or system-wide way.

Physical sensors are widely used in the field of oil and gasexploration, development and production, to measure and monitor physicalphenomena, such as temperatures, pressures, flow rates, and on/offstatus of pumps, motors, etc. Physical sensors often take directmeasurements of the physical phenomena and convert these measurementsinto measurement data to be further processed by control systems.Although physical sensors take direct measurements of the physicalphenomena, physical sensors and associated hardware are often costlyand, sometimes, unreliable. Further, when control systems rely onphysical sensors to operate properly, a failure of a physical sensor mayrender such control systems inoperable. For example, the failure of apressure sensor in a compressor station may result in a completeshutdown of the compressor station, even if the actual operatingconditions are within acceptable ranges. Physical sensors can be coupledwith an actuator, for example a physical sensor can be coupled with, orbe a part of an actuator that controls a device, such as a valve.

Actuators are devices that control either directly or indirectlymachinery commonly used in hydrocarbon exploration, development, andproduction operations. Actuators respond to commands and in an idealsituation, the devices work as designed. However, failure might happento one or more of the actuators. In this case, the outcome is thatdespite the obvious problem the system protects others and itself asmuch as possible. For example, a valve may be told to close but forwhatever reason it does not close all the way. Valves further downstreamthen should be instructed to close.

There is therefore, a need for systems and methods that providefail-safe interoperability among the various data sets, applications,and stakeholders sharing data across a production asset. There is also aneed for systems and methods that provide reliable sensing data to acontrol system.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective view of a plurality of boreholes inaccordance with at least some embodiments.

FIG. 2 shows a drilling system in accordance with at least someembodiments.

FIG. 3 shows a field production system in accordance with at least someembodiments.

FIG. 4 illustrates an exemplary block diagram of a virtual sensornetwork consistent with certain disclosed embodiments.

FIG. 5 illustrates a flowchart diagram of an exemplary virtual sensornetwork operational process consistent with certain disclosedembodiments.

FIG. 6 illustrates a flowchart diagram of an integrated system of oilfield monitoring and control consistent with certain disclosedembodiments.

FIG. 7 illustrates a flowchart diagram of an intelligent gateway portionof an integrated system of oil field monitoring and control consistentwith certain disclosed embodiments.

FIG. 8 illustrates a flowchart diagram of an intelligent edge applianceportion of an integrated system of oil field monitoring and controlconsistent with certain disclosed embodiments.

FIG. 9 illustrates a flowchart diagram of an ROC appliance portion of anintegrated system of oil field monitoring and control consistent withcertain disclosed embodiments.

FIG. 10 illustrates a flowchart diagram of a corporate cloud portion ofan integrated system of oil field monitoring and control consistent withcertain disclosed embodiments.

FIG. 11 illustrates a flowchart diagram of a computing unit that can beused with an integrated system of oil field monitoring and controlconsistent with certain disclosed embodiments.

DETAILED DESCRIPTION

The following detailed description illustrates embodiments of thepresent disclosure. These embodiments are described in sufficient detailto enable a person of ordinary skill in the art to practice theseembodiments without undue experimentation. It should be understood,however, that the embodiments and examples described herein are given byway of illustration only, and not by way of limitation. Varioussubstitutions, modifications, additions, and rearrangements may be madethat remain potential applications of the disclosed techniques.Therefore, the description that follows is not to be taken as limitingon the scope of the appended claims. In particular, an elementassociated with a particular embodiment should not be limited toassociation with that particular embodiment but should be assumed to becapable of association with any embodiment discussed herein.

As used herein the term “sensor” is meant to describe a device tomeasure and monitor physical phenomena, such as temperatures, pressures,flow rates, and on/off status of pumps, motors, etc. A physical sensorcan include or consist of an actuator, for example a physical sensor caninclude an actuator that controls a device, such as a valve. Further anactuator can control either directly or indirectly machinery while atthe same time measuring the physical position of said machinery. As usedherein the term sensor can be used to describe either a sensor, anactuator, or both.

There are many varied activities that are typically performed in theprocess of exploring, developing and operating oil, gas, geothermal andother fields. At a very high level these activities can include: basinmodeling; reservoir modeling; acquiring seismic data; leasing land;drilling exploratory wells; evaluating exploratory wells; drillingproduction wells; completing the production wells; and buildingfacilities to produce, collect, process, store, and transport theproduction from the wells.

Basin modeling involves studying the processes acting on rocks andfluids during the development of a sedimentary basin, such assimulations of sedimentation, burial, erosion, uplift, thermalproperties, pressure properties, and diagenesis prediction. Thesesimulations are generally applied to an entire basin or to largeportions of it.

Reservoir modeling concerns the present-day description of the rock andfluid properties in the subsurface in a localized area, without tryingto describe the means by which the reservoir arrived at its presentstate. Both basin modeling and reservoir modeling can be modified withthe additional information gathered during the drilling, evaluation andproduction phases of an individual field. The reservoir model isparticularly dynamic as it is constantly changing throughout the varioussegments of the production phases (primary, secondary, tertiaryproduction). The production of water and hydrocarbons from the reservoirand the injection of fluids or gas into the reservoir impose dynamiceffects on the reservoir, which should be reflected in the reservoirmodel.

While these activities require large expenditures of capital, theseexpenditures are viewed as investments in the hope of gaining revenues(e.g., from the sale of oil and gas) that exceed the total amount of theexpenditures. Thus, these activities may be referred to herein asinvestment activities. Each of the investment activities requiresvarious decisions, e.g., decisions regarding: how much land to lease andwhich parcels of land to lease; how to acquire the seismic data and howmuch seismic data to acquire; how many exploratory wells to drill andwhere to drill to the exploratory wells; how to develop fields; how manyproduction and injection wells to drill, where to drill the wells andwhat the well plan (i.e., the trajectory through space for the wellbore) should be for each of the production wells; how many perforationsto make for each well and how to distribute perforation locations alongthe well plan for each well; which order to drill and complete thewells; what size of processing facilities to construct and how toconnect the wells to the facilities; how to process the fluids producedfrom the reservoir; at what rate should a well be produced; at what rateshould a field be produced; in cases with a plurality of potentialproductive assets, which assets to develop, and in which order todevelop and produce the assets.

Other specific examples of decision variables can include: number ofwells; surface location of wells; size of pipelines; size ofcompressors; on-site storage capacity; production measurementcapabilities; well type (having attainable values such as horizontal,vertical or multilateral); well geometry; well drilling path; andplatform type (such as subsea and tension leg).

Furthermore, these decisions must be made in the context of a whole hostof fundamental variables, e.g., uncertainties in factors such as: thefuture prices of oil and gas leases; the amount of oil and/or gasreserves in a field; the shape and physical properties of reservoirs ineach field; the amount of time it will take to drill each exploratorywell and each production well; the availability of equipment such asdrilling rigs, drill pipe, casing, tubing and completion rigs;transportation limitations; the costs associated with operating andmaintaining production from the wells and related facilities; the costsassociated with operating and maintaining injection into the wells andrelated facilities; the stability of weather conditions; tax rates;royalty rates; profit-sharing percentages; ownership percentages (e.g.,equity interests); etc.

The output of a petroleum production system depends on its inputs,initial conditions, and operating constraints. The output of thepetroleum production system may be described in terms of productionprofiles of oil, gas and water for each of the production wells. Initialconditions on the reservoir may include initial saturations andpressures of oil, gas and water. Inputs may include profiles of fluid(e.g., water or gas) injection at the injection wells, and profiles ofpumping effort exerted at the production wells. Operating constraintsmay include constraints on the maximum production rates of oil, gas andwater per well (or per facility). The maximum production rates may varyas a function of time. Operating constraints may also include maximumand/or minimum pressures at the wells or facilities.

Global decision variables are decision variables that are not uniquelyassociated with a single asset. For example, the amount of capital to beavailable for the set of assets and the cost of capital is an example ofa global decision variable. Global uncertainty variables are uncertaintyvariables that are not uniquely associated with a single asset. Forexample, commodity pricing such as oil price is an example of a globaluncertainty variable.

The establishment of the wells and facilities of the petroleumproduction system involves a series of capital investments. Theestablishment of a well may involve investments to drill, perforate andcomplete the well. The establishment of a facility may involve acollection of processes such as engineering design, detailed design,construction, transportation, installation, conformance testing, etc.Thus, each facility has a capital investment profile that is determinedin part by the time duration and complexity of the various establishmentprocesses.

A commercial entity operating the petroleum production system may sellthe oil and gas liberated from the reservoir to generate a revenuestream. The revenue stream depends on the total production rates of oiland gas from the reservoir and the market prices of oil and gasrespectively. The commercial entity may operate its assets (e.g., wellsand facilities) under a set of fiscal regimes that determine tax rates,royalty rates, profit-sharing percentages, ownership percentages (e.g.,equity interests), etc. Examples of fiscal regimes include productionsharing contracts, joint venture agreements, and government tax regimes.

A person planning a petroleum production enterprise with respect to aset of reservoirs may use a reservoir simulator to predict the oil, gasand water production profiles of the petroleum production system. Thereservoir simulator may be supplied with descriptions of the systemcomponents (reservoirs, wells, facilities and their structure ofinter-connectivity) and descriptions of the system inputs, initialconditions and operating constraints.

Furthermore, the person may use an economic computation engine (e.g., aneconomic computation engine implemented in Excel or a similarspreadsheet application) to compute return as a function of time and/ornet present value. The economic computation engine may be supplied with:(a) a schedule specifying dates and costs associated with theestablishment of each facility and, dates and costs associated with theestablishment of each well (especially, production start datesassociated with each well); (b) fiscal input data (such as inflationrates, tax rates, royalty rates, oil and gas prices over time, operatingexpenses); and (c) the production profiles of oil, gas and waterpredicted by the reservoir simulator.

FIG. 1 shows a perspective cut-away view of several boreholes drilledinto underground formations. In particular, FIG. 1 shows the surface100, and six boreholes 102 (shown in dashed lines when obscured by thesurface, and solid lines otherwise), the boreholes drilled from thesurface 100.

Borehole 106 illustratively comprises a wellhead 108 at the surface 100,and a borehole 106 that extends from the wellhead 108 at the surface toan underground location. Each borehole (e.g., 106) is shown as avertical borehole; however, the layout of the wellheads and orientationof the boreholes is merely illustrative. In practice, the surfacelocation of wellheads may be seemingly random, and the boreholes may bedeviated boreholes, heading in any particular direction, includinghorizontal or lateral boreholes. The boreholes need not be hydrocarbonproducing boreholes. That is, any or all of the boreholes may be surveyboreholes, used to gather information for drilling further boreholesintended to be hydrocarbon producing. For example, one or more of theboreholes 102 may be “survey” wells used to gather information fordetermining placement of lateral boreholes in a shale formation.

Regardless of the layout, orientation or intended use of each borehole,each borehole will have at least one “log” associated with the borehole.“Log” used as a noun is a term of art referring to a set of data createdfrom “logging tools” moved through the borehole. The movement of thelogging tools may be: while the borehole is being drilled; before theborehole is drilled to its final depth, but during a period of time whenthe drill string has been removed from the borehole; or after theborehole is drilled to its final depth and the casing has been placedtherein. The verb “logging” is also a term of art that refers to theacts to acquire a log. In some cases, a log is a visual representationof the data, such as a line or graph that plots data with respect to anaxis that depicts depth where each datum is measured. In other cases, alog is a series of numbers correlated to depth (and from which thegraphical representation of the log may be created). The logs for eachborehole may identify multiple formations. That is, a log of a boreholemay identify, directly or indirectly, boundaries or transitions betweendifferent formation types. Each boundary may be a horizon of interest,and the location of each horizon within each borehole may be used tocreate an estimate or model of the formation parameters along a proposedadditional borehole 120.

Still referring to FIG. 1, the owner or operator may have plans to drillan additional borehole within the field, as illustrated by proposedborehole 120 (shown as a dash-dot-dash line). An estimate or model ofthe expected formation properties along the proposed borehole 120 can bemade using data from logs from some or all of the boreholes 102. Inaccordance with a particular embodiment, the estimate or model of theformation properties along the proposed borehole 120 can be updated inreal time as the borehole is being drilled (i.e., as the drill bit isturning and the drill string is advancing) along the proposed boreholepath. Sensors can be used to obtain and transmit log data and formationparameters.

In order to more fully describe the embodiments regarding updating theestimate or model of the formation property in real time while drilling,attention now turns to the illustrative drilling system of FIG. 2, whichshows a drilling operation in accordance with at least some embodiments.In particular, FIG. 2 shows a drilling platform 200 equipped with aderrick 202 that supports a hoist 204. Drilling in accordance with someembodiments is carried out by a string of drill pipes connected togetherby “tool” joints so as to form a drill string 206. The hoist 204suspends a top drive 208 that is used to rotate the drill string 206 andto lower the drill string through the wellhead 210. Connected to thelower end of the drill string 206 is a drill bit 212. The drill bit 212is rotated and drilling accomplished by rotating the drill string 206,or by use of a downhole “mud” motor near the drill bit 212 that turnsthe drill bit, or by both methods. Drilling fluid is pumped by mud pump214 through flow line 216, stand pipe 218, goose neck 220, top drive208, and down through the drill string 206 at high pressures and volumesto emerge through nozzles or jets in the drill bit 212. The drillingfluid then travels back up the borehole via the annulus 221 formedbetween the exterior of the drill string 206 and the borehole wall 222,through a blowout preventer (not specifically shown), and into a mud pit224 on the surface. On the surface, the drilling fluid is cleaned andthen circulated again by mud pump 214. The drilling fluid is used tocool the drill bit 212, to carry cuttings from the base of the boreholeto the surface, and to balance the hydrostatic pressure in the rockformations. The drilling operation includes multiple physical sensorssuch as weight-on-bit, rate of rotation, drilling fluid circulationrate, drilling fluid pump pressure, mud analysis data, etc.

In accordance with the various embodiments, the drill string 206 employsat least one logging-while-drilling (“LWD”) tool 226, and in some casesa measuring-while-drilling (“MWD”) tool 228. The distinction between LWDand MWD is sometimes blurred in the industry, but for purposes of thisspecification and claims, LWD tools measure properties of thesurrounding formation (e.g., porosity, permeability, speed of sound,electrical resistivity, drilling fluid invasion into the formation), andMWD tools measure properties associated with the borehole (e.g.,inclination, direction, downhole drilling fluid pressure, downholetemperature, mud cake thickness). The tools 226 and 228 may be coupledto a telemetry module 230 that transmits data to the surface. In someembodiments, the telemetry module 230 sends data to the surfaceelectromagnetically. In other cases, the telemetry module 230 sends datato the surface by way of electrical or optical conductors embedded inthe pipes that make up the drill string 206. In yet still other cases,the telemetry module 230 modulates a resistance to drilling fluid flowwithin the drill string to generate pressure pulses that propagate atthe speed of sound through the drilling fluid to the surface.

The LWD tool 226 may take many forms. In some cases, the LWD tool 226may be a single tool measuring particular formation parameters, such asa tool to measure natural gamma radiation from the formation, or anacoustic tool that actively interrogates the formation to determineproperties such as speed of sound, or differences in speed of soundalong different stress regimes. In other embodiments, the LWD tool 226may comprises a plurality of tools. For example, in many drillingsituations a suite of LWD tools is included in the drill string 206,such as the combination known in the industry as “triple-combination” or“triple-combo” suite of LWD tools. Though there may be slight variance,in most cases the triple-combo suite of logging tools comprises aneutron porosity tool, a density porosity tool, and a resistivity tool.No matter what type MWD/LWD tools are used, multiple sensors can be usedto obtain and transmit well and formation data.

Still referring to FIG. 2, in the illustrative case of data encoded inpressure pulses that propagate to the surface, one or more transducers,such as transducers 232, 234 and/or 236, convert the pressure signalinto electrical signals for a signal digitizer 238 (e.g., an analog todigital converter). While three transducers 232, 234 and/or 236 areillustrated, a greater number of transducers, or fewer transducers, maybe used in particular situations. The digitizer 238 supplies a digitalform of the pressure signals to a computer 240 or some other form of adata processing device. Computer 240 operates in accordance withsoftware (which may be stored on a computer-readable storage medium) toprocess and decode the received signals.

Turning to FIG. 3, an oilfield production field 300 is depictedincluding tanks, vessels and other machinery used to extract and processhydrocarbons, such as oil and gas, from subterranean formations. Dataobtained relating to the field 300 may include, for example,measurements of bottom hole pressure;

tubing head pressure; run status of pumps and compressors with relateddata such as pressure, temperature and flow rates; tank levels; pipelineflows and pressures; etc. Sensors can be used to monitor and transmitrelevant data. In an embodiment, a computer 302 at the field 300 can beused to gather the sensor data and to make that data available to aremote operating center (“ROC”).

A ROC is an operating center that is located away from the field orwell. For example, a ROC may enable a drilling engineer to be located inan office while in real time or near real time the engineer can overseethe various parameters of one or more wells being drilled in variouslocations distant from the engineer. Likewise a producing field 300 maybe instrumented to enable data to be transferred from a local device,such as a field device or computer 302, to an operating center that isremotely located in relation to the field.

As shown in FIG. 3, the oilfield production field 300 can include anumber of wells. Specifically, the oilfield production field 300includes a first producing well 304, which uses a pump jack 306 toproduce a hydrocarbon (e.g., oil, gas, etc.); a second well 308 is anatural flow production well; a third well 310 relies on a gas liftsystem 312 to produce a hydrocarbon; and a fourth well 314 produces ahydrocarbon utilizing an electric submersible pump 316. The first well304, second well 308, third well 310, and fourth well 314 are shown todeliver production fluids (e.g., hydrocarbon produced from theirrespective wells), via flow lines 317, 318, 320, and 322, to aproduction manifold 324. In an embodiment each well or flow line can beequipped with sensors to measure and transmit data such as pressure,temperature, flowrate and on/off status of equipment. The productionmanifold collects multiple streams and outputs the streams via flow line326 to a gas/oil/water separator 328. Physical sensors can include therun status of pump jack 306, casing and tubing pressures of well 304,casing and tubing pressures of well 308, casing and tubing pressures ofwell 312, gas lift injection rate and pressure of well 312, run statusof submersible pump 316, casing and tubing pressures of well 314,pressure on production manifold 324, pressure on separator 328, as wellas others. Upon receipt of the production fluids by the productionmanifold 324, the gas/oil/water separator 328 separates variouscomponents from the fluids, such as produced water, produced oil, andproduced gas.

The produced water leaves the gas/oil/water separator 328 and isdirected via flow line 330 to water storage tank 338 that contains anoutlet 340 where water can be removed, such as by a truck for haulingoff produced water. Alternately water can be directed via flow line 342to a water disposal well 344. The water tank contains a level indicator346, such as a sight glass equipped with a level transmitter. Physicalsensors can include fluid level in tank 338, water flow rate to disposalwell 344, pressure on well 344 as well as others.

The produced oil leaves the gas/oil/water separator 328 and is directedvia flow line 332 to oil storage tank 350 that contains an outlet 352where oil can be removed, such as by a truck for hauling off producedoil. Alternately, oil can be directed via flow line 354 to a leaseautomatic custody transfer (“LACT”) unit 356 for measurement prior toflow into an oil export pipeline 358. The oil storage tank 350 containsa level indicator 360, such as a sight glass equipped with a leveltransmitter. Physical sensors can include fluid level in tank 350, oilflow rate through LACT unit 356, pressure on pipeline 358, as well asothers.

The produced gas leaves the gas/oil/water separator 328 and is directedvia flow line 334 to a compressor station 364. The compressor station364 may deliver gas to a gas pipeline 366 or may deliver some gas viaflow line 368 to be used as an injection gas for the gas lift system 312of the third well 310. In order to adjust pressure on the injection gas,a meter and control system 370 may regulate pressure of the injectiongas to the gas lift system 312. Physical sensors can include gas flowrate through flow line 334, pressure on flow line 334, operationalparameters of compressor station 364, sensor/actuator position ofcontrol system 370, flow rate of gas to the gas lift system 312, flowrate of gas to the gas pipeline 366, pressure on gas pipeline 366, aswell as others.

Physical sensors are sensors for measuring certain parameters of theoilfield operation, such as for example temperature, speed, flow rate,fuel pressure, power output, etc. A virtual sensor, as used herein, mayrefer to a mathematical algorithm or model that produces output measurescomparable to a physical sensor based on inputs from other systems, suchas physical sensors and/or actuators. The term “virtual sensor” may beused interchangeably with “virtual sensor model.”

As shown in FIG. 4, a virtual sensor 400 may include a virtual sensormodel 404, input parameter value 402, and output parameter value 406.Virtual sensor model 404 may be established to link (e.g. buildinterrelationships) between input parameter values 402 (e.g., measuredparameter values) and output parameter values 406 (e.g., sensingparameter values). After virtual sensor model 404 is established, inputparameter values 402 may be provided to virtual sensor model 404 togenerate output parameter values 406 based on the given input parametervalues 402 and the interrelationships between input parameter values 402and output parameter values 406 established by virtual sensor model 404.In an embodiment the virtual sensor model compares the input values witha pre-established range of acceptable values and can determine if theinput value is reliable and if not can alter the output value inresponse.

A virtual sensor network, as used herein, may refer to a collection ofvirtual sensors integrated and working together using certain controlalgorithms such that the collection of virtual sensors may provide moredesired or more reliable sensor output parameters than discreteindividual virtual sensors. Virtual sensor network 400 may include aplurality of virtual sensors configured or established according tocertain criteria based on a particular application. Virtual sensornetwork 400 may also facilitate or control operations of the pluralityvirtual sensors. The virtual sensors may include any appropriate virtualsensor providing sensor output parameters corresponding to one or morephysical sensors. In an embodiment the virtual sensor network can employvirtual sensors that all use the same type of interface to enablestandardization throughout the network.

As shown in FIG. 5, an embodiment of a method includes the step ofobtaining model information of a virtual sensor 502. This may includeobtaining model types, model data including valid input spaces andcalibration data used to train and optimize the model, and statisticaldata, such as distributions of input and output parameters of thevirtual sensor model 400. Data from the physical sensors that providedata to the virtual sensor model can include input and output parametersof the physical sensors and operational status of the physical sensors.

Further, the method can determine interdependency among the plurality ofvirtual sensor models based on the model information 504.Interdependency, as used herein, may refer to any dependency between twoor more virtual sensor models. For example, the interdependency betweentwo virtual sensor models may refer to existence of a feedback from onevirtual sensor model to the other virtual sensor model, either directlyor indirectly. That is, one or more output parameters from one virtualsensor model may be directly or indirectly fed back to one or more inputparameters of the other virtual sensor model.

The method may also monitor and control individual virtual sensors 506.For example, for a backup virtual sensor, i.e., a secondary virtualsensor becomes operational upon a predetermined event to replace acorresponding initial virtual sensor if output parameters of the initialvirtual sensor model outside of a predetermined deviation from aprojected output. A deviation between the predicted values and theactual values can be calculated and may determine whether the deviationis beyond a predetermined threshold. If any individual input parameteror output parameter is out of the respective range of the input space oroutput space, an alarm may be sent and the system may apply anyappropriate algorithm to maintain the values of input parameters oroutput parameters in the valid range to maintain operation with areduced capacity.

The method may also determine collectively whether the values of inputparameters are within a valid range. A comparison of valid values can beperformed. For example, a Mahalanobis distance can be calculated todetermine if an input parameter is within normal operational ranges ofinput values. A Mahalanobis distance is a measure of the distancebetween an individual point and a distribution of values. It is unitless and scale-invariant, and takes into account the correlations of thedata set. Mahalanobis distance differs from Euclidean distance in thatMahalanobis distance takes into account the correlations of the dataset. Mahalanobis distance of a data set X (e.g., a multivariate vector)may be represented as

MD_(i)=(X_(i)−μ_(x))Σ⁻¹(X_(i)−μ_(x))′ (1) where μ_(x) is the mean of Xand Σ⁻¹ is an inverse variance-covariance matrix of X MD_(i) weights thedistance of a data point X from its mean μ_(x) such that observationsthat are on the same multivariate normal density contour will have thesame distance.

During initial calibration and optimizing virtual sensor models, a validMahalanobis distance range for the input space may be calculated andstored as calibration data associated with individual virtual sensormodels. A Mahalanobis distance can be calculated for input parameters ofa particular virtual sensor model as a validity metric of the validrange of the particular virtual sensor model. If the calculatedMahalanobis distance exceeds the range of the valid Mahalanobis distancerange stored in the virtual sensor network an alarm may be sent to othercomputer programs, control systems, or a user to indicate that theparticular virtual sensor may be unfit to provide predicted values.Other validity metrics may also be used. For example, each inputparameter can be compared against an established upper and lower boundsof acceptable input parameter values.

After monitoring and controlling individual virtual sensors, virtualsensor network controller may also monitor and control collectively aplurality of virtual sensor models 508. That is, it may determine andcontrol operational fitness of virtual sensor network and may monitorany operational virtual sensor model of virtual sensor models. It mayalso determine whether there is any interdependency among anyoperational virtual sensor models including the virtual sensor modelsbecoming operational. If it is determined there is interdependencybetween any virtual sensor models, it may determine that theinterdependency between the virtual sensors may have created a closedloop to connect two or more virtual sensor models together, which isneither intended nor tested. It may then determine that the virtualsensor network may be unfit to make predictions, and may send an alarmor report to control systems or users. It may indicate as unfit onlyinterdependent virtual sensors while keeping the remaining virtualsensors in operation.

As used herein, a decision that a virtual sensor or a virtual sensornetwork is unfit is intended to include any instance in which any inputparameter to or any output parameter from the virtual sensor or thevirtual sensor network is beyond a valid range or is uncertain; or anyoperational condition affect the predictability and/or stability of thevirtual sensor or the virtual sensor network. An unfit virtual sensornetwork may continue to provide sensing data to other control systemsusing virtual sensors not affected by the unfit condition, suchinterdependency, etc.

In certain embodiments, a single computer at the wellsite or field canbe used to gather all required data and to make that data availablethrough a remote operating center. Single computer operation of thesurface equipment reduces complexity and allows for much faster andsimpler installation at the wellsite and in some cases may allow theMWD/LWD system to travel along with the rig equipment, eliminating theneed for per well assembly and disassembly entirely.

The overview of an embodiment of the architecture is shown in FIG. 6.The architecture 600 is shown in three segments, an Oil Field segment602, a Regional ROC segment 604, and a Corporate segment 606. Within theOil Field segment 602 there are a plurality of Sensors 610, a pluralityof Intelligent Gateways 612 and an Edge Appliance 614. The Regional ROCsegment 604 contains a ROC Appliance 620. The Corporate segment 606contains a Corporate Cloud 630.

Apart from the physical sensors 610 in the leftmost layer, architectureconsists of four major distributed components from left to right namely:intelligent gateway 612, intelligent edge appliance 614, ROC appliance620, and corporate cloud 630. These four components grow in scope andscale by acquiring data from one or more instances of components in theprevious layers. Similarly, each component adds intelligence andsemantics to the data from the previous layers. Each of these componentsutilizes a secured Application Programmable Interface (API) to interactwith the external components. In an embodiment each component utilizes acompatible API that can integrate with other components API, and in afurther embodiment each component utilizes the same type API to ensureintegration between the components.

Deployment of the software to these four components is through acontainer that provides a unique namespace for every application. Thismethodology not only provides isolation between the differentapplications but it also eases distribution since the container'sstandard interfaces makes the container easy to deploy. The containersare grouped into functions based on their respective roles following astandardized microservice design pattern. The different areas can beseen in FIGS. 6-9.

Physical sensors 610, which herein can be sensors and/or actuators, aretypically part of the devices installed either on the surface or thesubsurface in an oilfield. These devices assist with the equipment thatperforms the drilling, measurement while drilling (MWD), logging whiledrilling (LWD), wireline logging, performance evaluation (PE),Distributed Acoustic Sensing (DAS), cementing, and field control. Thesesensors, which gather data, can be either temporarily or permanentlyinstalled. The different sensors discover each other and can communicatewith each other as required. The control of the physical device isthrough a logical layer known as the logical actuator. As with thelogical sensors, the actuators discover each other and can communicatewith each other as required. As used herein the term sensor will includean actuator.

Intelligent Gateway Appliance The next level up from the sensor 610 isthe logical layer, also known as an intelligent gateway 612, or as avirtual sensor, that obtains data from physical sensors. The virtualsensors can be designed and deployed via a user interface (“UI”) that ispresent at the intelligent gateway as well as at the higher levels inthe system. In an embodiment, the system and methods disclosed hereinuse the same basic UI metaphors as well as implementations at everylevel of the platform. This uniformity makes development easier and thesubsequent use and maintenance consistent throughout, which in turneases use and lowers costs. The design time tool constructs the virtualsensor's output value(s) with appropriate engineering units from theoutput of one or more physical sensors. It also translates any virtualinputs into commands the physical device understands. The virtual sensoruses deep learning for signal conditioning and signal analysis.

This component is detailed further in FIG. 7. The intelligent gateway700 obtains data from physical sensors & actuators 702 and provides aninterface, physical sensor API 704 that provides a uniform way to accesshardware in the oilfield and a uniform API for higher layers to interactwith. The primary purposes of this layer are sensing data and respondingto commands as soon as any anomaly or fault is detected. The intelligentgateway can include a Protocol and Device Abstraction 706, DataPreprocessing 708, a Data Processing Engine 710, a Deep LearningIntelligent Agent 712, a Sensor Lookup and Discovery 714, Command andQuery Responsibility Segregation (CQRS) 716, and a Data Store 718. Theintelligent gateway also hosts the deep learning models 720 required forvalidation, calibration, signal processing, intelligence, compression,and predictive control. The intelligent gateway 700 can also include aWEB Server 722, and a UI 724. The UI 724 can include a Virtual SensorDesign, Test and Deploy 726 function, a Virtual Sensor Data StreamVisualization 728 function, a Command Interface 730, an Event,Notifications, Recommendations 732 function and an Admin Console 734. AContent Delivery Client 736 function can receive content from a FieldSensor API 738. A Gateway Sensor API 740 is also available. Output fromthe intelligent gateway 700 is a Virtual Sensor Data Stream from theGateway 742.

Writing data, querying data and sending actuator is through a designpattern known as Command and Query Responsibility Segregation (CQRS)716. A part of this component allows virtual sensors to be defined froma combination of physical sensors. A virtual sensor is similar to aprocess with inputs typically from one or more physical sensors that isacted upon by the transformation functions to produce output. Virtualsensors are defined through the UI based designer & tester; the definedvirtual sensors once deployed are executed by a data processing engine.Other UIs include both raw and processed data, events, notifications andrecommendations 732 from a deep learning agent, console 734 toadminister the edge gateway and command interface 730 to issue controlcommands via CQRS 716 to actuators. This UI can be also accessed from aperson in the field or from a ROC given appropriate authority as well asconnectivity via standard web protocols. This component provides agateway sensor API 740 for higher layers to communicate with thiscomponent and the underlying sensor/actuators. By necessity, thesensor/actuator device is found near to the physical hardware used foracquisition and control.

The intelligent gateway 700 level can receive inputs via the physicalSensor API 704 and incorporate into its deep learning data such asnon-limiting examples: pressure, temperature, flowrate, level indicator,on/off status, etc.

Intelligent Edge Appliance The next level in the oilfield is theintelligent edge appliance as shown in FIG. 6 as item 614. Dataaggregation happens at this device and more complicated deep learninghappens here as the result of having more computation resources. Theedge appliance 614 provides a UI that allows interaction with thephysical devices through the logical layer using dynamic deep layermodels. The UI also gives a place to create all the virtual devices, toadministrate the system, and to run any required tests. The intelligentedge appliance 800, shown in FIG. 8, collects information from all theidentified intelligent gateway devices via gateway sensor API 802,stores the information for later retrieval, and provides for extracompute capacity for deep learning that is not available on theintelligent gateway devices. The appliance is normally within closerange of a group of Sensor/Actuator devices. Interactions by theoperator (Human in the Loop) typically happens at the intelligent edgeappliance, but may happen at other levels also. The appliance candeliver content to the ROC as well as passing on actuator commands tothe predictive control system. The appliance has more resources and thuscan run more compute intensive models than what can be executed on theedge appliance. The interaction with the data is once again using theCQRS pattern. The UI details presented here are the same as with theedge with the difference that the appliance has the views that aggregateinformation from multiple intelligent gateways to provide view of theentire oilfield. This component can define another set of virtualsensors on top of the virtual sensors defined in multiple intelligentgateways consumed by this component. A similar UI is used to definevirtual sensors at this level, as was used in the intelligent gatewaycomponent. This component includes a Field sensor API that is used tocommunicate with the ROC appliance component. Other UIs include both rawand processed data, events/notifications, recommendations from deeplearning agent, console to administer the intelligent edge appliance andcommand interface to issue control commands via CQRS to the gatewaysensor API that can be eventually delivered to the physical actuators.

This component is detailed further in FIG. 8. The intelligent edgeappliance 800 abstracts Virtual Sensor Data Stream 802 from theintelligent gateways and provides an interface, Gateway sensor API 804,that provides a uniform way to access all hardware in the oilfield and auniform API for higher layers to interact with. The intelligent edgeappliance 800 can include a Stream Consumer 806, Data Preprocessing 808,a Data Processing Engine 810, a Deep Learning Intelligent Agent 812, aGateway Sensor Lookup 814, CQRS Interface 816 and a Data Store 818. Theintelligent gateway also hosts the deep learning models 820 required forvalidation, calibration, signal processing, intelligence, compression,and predictive control. The edge appliance 800 can also include a WEBServer 822, and a UI 824. The UI 824 can include a Virtual SensorDesign, Test and Deploy 826 function, a Virtual Sensor Data StreamVisualization (Field View) 828 function, a Command Interface 830, anEvents, Notifications, Recommendations 832 function and an Admin Console834. A Content Delivery Client 836 function can receive content from aROC API 838. A Field Sensor API 840 is also available. Output from theintelligent edge appliance 800 is a Virtual Sensor Data Stream from theField 842 which can then be used by the higher levels.

The intelligent edge appliance 800 level can receive inputs via theField Sensor API 840 and incorporate into its deep learning data such asnon-limiting examples: the capacity of facilities to produce, collect,process, store, and transport the production from the wells; localweather information; transportation limitations on moving rigs andequipment; transportation limitations on gas and oil pipelines andrailcar traffic; facility design including engineering design, detaileddesign, construction, transportation, installation, conformance testing,etc.

Realtime Operations Center (ROC) Appliance—The next level in theoilfield is the ROC appliance as shown in FIG. 6 as item 620. The ROCappliance 620 is almost identical to the edge appliance 614 with thefollowing differences. The ROC appliance 620 typically has morecomputing capacity than the edge appliance 614, thus large deep learningmodels are possible here as well as more storage is available. Commandof the oilfield facilities though the virtual actuators can happen hereif required, but latency may be a factor in what commands are allowed.The ROC appliance 900, shown in FIG. 9, collects information from allthe identified edge appliance devices 800 via field sensor API 902,stores the information for later retrieval, and provides for extracompute capacity for deep learning that is not available on the edgegateway device.

This component is detailed further in FIG. 9. The ROC appliance 900abstracts Virtual Sensor Data Stream from Fields 902 from the edgeappliances and provides an interface, Field sensor API 904 that providesa uniform API for other layers to interact with. The ROC appliance 900can include a Stream Consumer 906, Data Preprocessing 908, a DataProcessing Engine 910, a Deep Learning Intelligent Agent 912, a FieldSensor Lookup 914, CQRS Interface 916 and a Data Store 918. The ROCappliance 900 also hosts the deep learning models 920 required forvalidation, calibration, signal processing, intelligence, compression,and predictive control. The ROC appliance 900 can also include a WEBServer 922, and a UI 924. The UI 924 can include a Virtual SensorDesign, Test and Deploy 926 function, a Virtual Sensor Data StreamVisualization (Region View) 928 function, a Command Interface 930, anEvent, Notifications, Recommendations 932 function and an Admin Console934. A Content Delivery Client 936 function can receive content from aCorporate API 938. A ROC Sensor API 940 is also available. Output fromthe ROC appliance 900 is a Virtual Sensor Data Stream from the ROC 942,which can then be used by the higher levels.

The ROC appliance 900 level can receive inputs via the ROC Sensor API940 and incorporate into its deep learning data such as non-limitingexamples: the stability of local and regional weather conditions; thesize and capacity of processing facilities; amount of oil and/or gasreserves in a field; the shape and physical properties of reservoirs ineach field; reservoir modeling; the amount of time it will take to drilleach exploratory well and each production well; the availability ofequipment such as drilling rigs, drill pipe, casing, tubing andcompletion rigs; transportation limitations; the costs associated withoperating and maintaining production from the wells and relatedfacilities; the costs associated with operating and maintaininginjection wells and related facilities; optimized production rates fromthe reservoir; reservoir decline profiles; optimized production ratesfrom the field; in cases with a plurality of potential productiveassets, which assets, and which order to develop and produce the assets;etc.

Corporate Layer Above the ROC is the Corporate cloud. The Corporatecloud level has no practical limits and it allows even larger executionof deep learning models. The Corporate cloud also has access toinformation that is not available at the lower levels of thearchitecture. These are the two primary differences between this layerand the ROC. The corporate layer shown in FIG. 10 gathers all the datafrom the ROC appliance layer via the ROC API and can process it incontext of other enterprise data sources such as CRM, Sales, Pricing,Procurement etc. and can generate near real time recommendations forROCs to change operating plans in global context. It executes on asystem with unconstrained resources allowing large deep learning modelsthan what could be run on the other parts of the system. Because itgathers data from multiple oilfields, date store in this component iscomparable in scale with modern big data stores. This component can alsodefine its own set of virtual sensors on top of the sensors created inthe “ROC appliance” layer. Similar UI is used to define, test and deployvirtual sensors as was used in previous components. Other UIs includeboth raw and processed data, events/notifications, and recommendationsfrom deep learning agent, console to administer the Corporate cloud.This layer also exposes “Corporate API” used to the programminginterfaces are the same as the other layers.

This component is detailed further in FIG. 10. The Corporate cloud level1000 abstracts Virtual Sensor Data Stream from ROCs 1002 from the ROCappliances and provides an interface, ROC sensor API 1004 that providesa uniform API for other layers to interact with. The Corporate cloud1000 can include a Stream Consumer 1006, Data Preprocessing 1008, a DataProcessing Engine 1010, a Deep Learning Intelligent Agent 1012, a ROCSensor Lookup 1014, CQRS Interface 1016, a Data Store 1018 and Other ERPData Services 1019. The Corporate cloud 1000 also hosts the deeplearning models 1020 required for validation, calibration, signalprocessing, intelligence, compression, and predictive control. TheCorporate cloud 1000 can also include a WEB Server 1022, and a UI 1024.The UI 1024 can include a Virtual Sensor Design, Test and Deploy 1026function, a Virtual Sensor Data Stream Visualization (Global View) 1028function, a Command Interface 1030, an Events, Notifications,Recommendations 1032 function and an Admin Console 1034. A Corporate API1040 is also available.

The Corporate cloud 1000 level can receive inputs via the Corporate API1040 and incorporate into its deep learning data such as non-limitingexamples: the future prices of oil and gas; tax rates; royalty rates;profit-sharing percentages; ownership percentages (e.g., equityinterests); basin modeling; reservoir modeling; seismic data; leasedland holdings; regional climate considerations; etc.

There are several distinctive features in the present disclosure thatset it apart from what is in use today. These distinctive featuresinclude the use of a uniform API throughout the system. The proposedsystem maintains the same (or compatible) interface type from the top ofthe architectural stack to the bottom. Details of this uniformityinclude CQRS, microservices, data storage, deep machine algorithms, andUI. This approach of using one standard blueprint for the entire systemdramatically lowers development and maintenance costs of the system andprovides ease of use at all levels.

Other solutions utilize multiple different ways to interact with thedata. The present disclosure uses the same basic UI metaphors as well asimplementations at every level of the platform. The approach describedherein makes development easier due to the uniformity, which in turnlowers costs.

Other solutions require and use different distribution mechanisms thatmake it difficult to upgrade one part of the system without impactingother sections. The present disclosure uses a container that holds allof the executable code and its dependencies that run in their ownnamespace. The use of a uniform distribution mechanism enables upgradingof one part of the system without impacting other sections.

The acquisition, calibration, and analysis of the data at every layer inthe system is performed by deep learning models. The interaction withthe actuators follows the same pattern of using deep learning models.

Unlike what others have proposed, this disclosure has several differentlayers that work together. This allows a variety of scopes to beintroduced into the different machine learning algorithms that takeadvantage of having a wider viewpoint as the architectural layers widen.

The present disclosure provides deep learning algorithms that canpredict behaviors that might be suboptimal and warn an operator aboutwhat is projected to happen. The ability to easily have humaninteraction within the system is also a major benefit. Having a human inthe loop (HITL) provides oversight and operational interaction withinthe system.

There are commercial competitive advantages of the present inventionthat include optimal solutions, forecasting, and insights. The deeplearning models can construct the best solution for tasks such asremoving noise and keeping the instrument calibrated properly. Theeconomic advantage of this single feature is hard to overestimate.Typical solutions are less than optimal, which impacts both the bottomline and safety. The deep learning model can predict what is happeningat every stage of the system and inform the human of the situation. Thisnotification for example can take the form of alerting the operator thatthe proposed action is required. The information could also includetrends that include when service needs to be performed. Another exampleis ordering consumables before the current supply is exhausted. Thefeedback given by the deep learning models to the human will helpimprove safety, decrease environmental accidents, and keep the systemoperating at peak efficiency.

The deep learning models can give information about the data that wouldotherwise costly to find. For example, the models can identify whenmaintenance is required on a device based on its wear in the field. Itcan remove the signal of the sensors from the noise and identify the keytrends that indicate items such as a pay zone or a poor cementing job.

System Description

The present disclosure may be implemented through a computer-executableprogram of instructions, such as program modules, generally referred tosoftware applications or application programs executed by a computer.The software may include, for example, routines, programs, objects,components, and data structures that perform particular tasks orimplement particular abstract data types. The software forms aninterface to allow a computer to react according to a source of input.DecisionSpace® Desktop, which is a commercial software applicationmarketed by Landmark Graphics Corporation, may be used as an interfaceapplication to implement the present disclosure. The software may alsocooperate with other code segments to initiate a variety of tasks inresponse to data received in conjunction with the source of the receiveddata. The software may be stored and/or carried on any variety of memorysuch as CD-ROM, magnetic disk, bubble memory and semiconductor memory(e.g., various types of RAM or ROM). Furthermore, the software and itsresults may be transmitted over a variety of carrier media such asoptical fiber, metallic wire, and/or through any of a variety ofnetworks, such as the Internet.

Moreover, those skilled in the art will appreciate that the disclosuremay be practiced with a variety of computer-system configurations,including hand-held devices, multiprocessor systems,microprocessor-based or programmable-consumer electronics,minicomputers, mainframe computers, and the like. Any number ofcomputer-systems and computer networks are acceptable for use with thepresent disclosure. The disclosure may be practiced indistributed-computing environments where tasks are performed byremote-processing devices that are linked through a communicationsnetwork. In a distributed-computing environment, program modules may belocated in both local and remote computer-storage media including memorystorage devices. The present disclosure may therefore, be implemented inconnection with various hardware, software or a combination thereof, ina computer system or other processing system.

Referring now to FIG. 11, a block diagram illustrates one embodiment ofa system for implementing the present disclosure on a computer. Thesystem includes a computing unit 1100, sometimes referred to as acomputing system, which contains memory 1102, application programs 1104,1106, a client interface 1108, a video interface 1110, and a processingunit 1112. The computing unit 1100 is only one example of a suitablecomputing environment and is not intended to suggest any limitation asto the scope of use or functionality of the disclosure.

The memory 1102 primarily stores the application programs, which mayalso be described as program modules containing computer-executableinstructions, executed by the computing unit 1100 for implementing thepresent disclosure described herein. In an illustrative example thememory 1102, includes a basin-to-reservoir modeling module 1104, whichcan be a portion of the method described in the present disclosure. Inparticular, DecisionSpace® Desktop 1106 may be used as an interfaceapplication to perform at least a portion of the method described in thepresent disclosure. Although DecisionSpace Desktop 1106 may be used asthe interface application, other interface applications may be usedinstead, or the basin-to-reservoir modeling module 1104 may be used as astand-alone application. DecisionSpace Desktop is commercially availablefrom Landmark Graphics Corporation of Houston, Tex.

Although the computing unit is shown as having a generalized memory1102, the computing unit typically includes a variety of computerreadable media. By way of example, and not limitation, computer readablemedia may comprise computer storage media and communication media. Thecomputing system memory may include computer storage media in the formof volatile and/or nonvolatile memory such as a read only memory (ROM)and random access memory (RAM). A basic input/output system (BIOS),containing the basic routines that help to transfer information betweenelements within the computing unit, such as during start-up, istypically stored in ROM. The RAM typically contains data and/or programmodules that are immediately accessible to and/or presently beingoperated on by the processing wilt. By way of example, and notlimitation, the computing unit includes an operating system, applicationprograms, other program modules, and program data.

The components shown in the memory 1102 may also be included in otherremovable/nonremovable, volatile/nonvolatile computer storage media orthey may be implemented in the computing unit through an applicationprogram interface (“API”) or cloud computing, which may reside on aseparate computing unit connected through a computer system or network.By way of example only, a hard disk drive may read from or write tononremovable, nonvolatile magnetic media, a magnetic disk drive may readfrom or write to a removable, nonvolatile magnetic disk, and an opticaldisk drive may read from or write to a removable, nonvolatile opticaldisk such as a CD ROM or other optical media. Otherremovable/non-removable, volatile/nonvolatile computer storage mediathat can be used in the exemplary operating environment may include, butare not limited to, magnetic tape, flash memory cards, digital versatiledisks, digital video tape, solid state RAM, solid state ROM, and thelike. The drives and their associated computer storage media discussedabove provide storage of computer readable instructions, datastructures, program modules and other data for the computing unit.

A client may enter commands and information into the computing unitthrough the client interface 1108, which may be input devices such as akeyboard and pointing device, commonly referred to as a mouse, trackballor touch pad. Input devices may include a microphone, joystick,satellite dish, scanner, or the like. These and other input devices areoften connected to the processing unit 1112 through the client interface1108 that is coupled to a system bus, but may be connected by otherinterface and bus structures, such as a parallel port or a universalserial bus (USB).

A monitor or other type of display device may be connected to the systembus via an interface, such as a video interface. A graphical userinterface (“GUI”) may also be used with the video interface to receiveinstructions from the client interface and transmit instructions to theprocessing unit. In addition to the monitor, computers may also includeother peripheral output devices such as speakers and printer, which maybe connected through an output peripheral interface.

Although many other internal components of the computing unit are notshown, those of ordinary skill in the art will appreciate that suchcomponents and their interconnection are well known.

Embodiments of the present disclosure include a method of operating anoilfield device that includes providing a physical sensor, a virtualsensor, and establishing interdependencies between the physical sensorand virtual sensor. A physical sensor data stream relating to anoilfield device is obtained. Using the physical sensor data stream asinput data to the virtual sensor a virtual sensor output data stream isgenerated, and the virtual sensor output data stream is used to controlthe oilfield device.

The method can further include determining whether the physical sensordata stream is reliable or determining whether the physical sensor datastream is within a predetermined acceptable range. The physical sensorcan be selected from the group of: acoustic sensor, chemical sensor,density sensor, electrical sensor, flow sensor, hydraulic sensor, levelsensor, magnetic sensor, mechanical sensor, optical sensor, positionsensor, pressure sensor, proximity sensor, thermal sensor, vibrationsensor, and combinations thereof.

The physical sensor data stream can be used as input data to the virtualsensor utilizing a physical sensor application programmable interface(API); and the virtual sensor data stream can be sent to a controlsystem utilizing an API that is compatible with the physical sensor API.The virtual sensor can be with other virtual sensors to form a virtualsensor network. The method can optionally include obtaining virtualsensor model information; determining interdependencies among virtualsensor models; monitoring and controlling individual virtual sensormodels; and monitoring and controlling the virtual sensor network. Thevirtual sensor can be an intelligent gateway that includes dataprocessing, data storage, deep learning, a user interface, and a gatewaysensor API; the method further including generating a virtual sensordata stream from gateway.

The physical sensor data stream can be used as input data to the virtualsensor utilizing a physical sensor application programmable interface(API); and the virtual sensor data stream can be sent to a controlsystem utilizing an API that is compatible with the physical sensor API.The virtual sensor can be with other virtual sensors to form a virtualsensor network. The method can optionally include obtaining virtualsensor model information; determining interdependencies among virtualsensor models; monitoring and controlling individual virtual sensormodels; and monitoring and controlling the virtual sensor network. Thevirtual sensor can be an intelligent gateway that includes dataprocessing, data storage, deep learning, a user interface, and a gatewaysensor API; the method further including generating a virtual sensordata stream from gateway.

The intelligent gateway can optionally exchange data with a physicalsensor using the physical sensor API and receive data from an edgeappliance using a field sensor API. In an embodiment the field sensorAPI, gateway sensor API, and the physical sensor API are compatible.

The method can optionally include using the virtual sensor data streamfrom gateway as input data to the edge appliance utilizing the gatewaysensor API; analyzing the virtual sensor data stream from gateway withinthe edge appliance, the edge appliance comprising data processing, datastorage, deep learning, a user interface, and a field sensor API; themethod further including generating a virtual sensor data stream fromfield. The edge appliance can optionally provide data to the intelligentgateway using the field sensor API and receive data from a realtimeoperations control (ROC) appliance using a ROC API. The ROC API, fieldsensor API, gateway sensor API, and the physical sensor API can becompatible. In an embodiment, the method further includes using thevirtual sensor data stream from field as input data to a ROC applianceutilizing the field sensor API; analyzing the virtual sensor data streamfrom field within the ROC appliance, the ROC appliance comprising dataprocessing, data storage, deep learning, a user interface, and a ROCAPI; the method further including generating a virtual sensor datastream from ROC.

The ROC appliance can provide data to an edge appliance using the ROCAPI and receive data from a corporate appliance using a corporate API.The corporate API, ROC API, field sensor API, gateway sensor API, andthe physical sensor API can all be compatible with each other.

In an optional embodiment the method can include using the virtualsensor data stream from ROC as input data to a corporate applianceutilizing a ROC API; analyzing the virtual sensor data stream from ROCwithin the corporate appliance, the corporate appliance comprising dataprocessing, data storage, deep learning, a user interface, and acorporate API. The intelligent gateway, edge appliance, ROC applianceand corporate appliance can each contain a deep learning model forvalidation, calibration, signal processing, intelligence, compression,and predictive control. The intelligent gateway, edge appliance, ROCappliance and corporate appliance can each contain a command and queryresponsibility segregation (CQRS) interface that enables writing dataand receiving data from data storage, querying data, and issuing controlcommands to actuators.

An alternate embodiment is a virtual sensor network system for managingoilfield activity with a control system that includes a plurality ofvirtual sensors, each having a model type, at least one input parameter,and at least one output parameter that are integrated into a virtualsensor network. Also included are an input interface to obtain data fromcorresponding physical sensors an output interface to provide data to acontrol system, and a controller configured to: determineinterdependencies among the plurality of virtual sensors; obtainoperational information of the plurality of virtual sensors; and provideone or more virtual sensor output parameters to the control system basedon the determined interdependencies and the operational information.

The virtual sensor network system can optionally include where theplurality of virtual sensors are integrated by: obtaining data recordscorresponding to the plurality of virtual sensors; obtaining model andconfiguration information of the plurality of virtual sensor;determining applicable model types of the plurality of virtual sensorsand corresponding accuracy; selecting a combination of model types forthe plurality of virtual sensors; and calculating an overall accuracy ofthe virtual sensor network based on the combination of model types ofthe plurality of virtual sensors.

The virtual sensor network system can further include where, todetermine the interdependencies, the controller is further configuredto: determine a feedback relationship between the output parameter ofone virtual sensor from the plurality of virtual sensors and the inputparameter of one or more of other virtual sensors from the plurality ofvirtual sensors; and store the feedback relationship in a table.

In an optional embodiment, the controller is further configured to:determine a first condition under which the virtual sensor network isunfit to provide one or more virtual sensor output parameters to thecontrol system based on the determined interdependencies and theoperational information; and present the determined first condition tothe control system to indicate the determined first condition. Todetermine the first condition, the controller can be further configuredto: monitor the interdependencies of the plurality of virtual sensors;and determine occurrence of the first condition when two or more virtualsensors are both interdependent and providing the sensing data to thecontrol system.

In an optional embodiment, the controller is further configured to:determine a second condition under which an individual virtual sensorfrom the virtual sensor network is unfit to provide the output parameterto the control system; and present the second condition to the controlsystem to indicate the determined second condition.

In an optional embodiment, the controller is further configured to:obtain values of the input parameter of a virtual sensor; calculate aMahalanobis distance based on the obtained values; determine whether thecalculated Mahalanobis distance is within a valid range; determine thesecond condition if the calculated Mahalanobis distance is not withinthe valid range.

The virtual sensor can be an intelligent gateway that includes dataprocessing, data storage, deep learning, a user interface, and a gatewaysensor API; that generates a virtual sensor data stream from gateway.The virtual sensor network system can further include: an intelligentgateway capable of exchanging data with a physical sensor using aphysical sensor API and receiving data from an edge appliance using afield sensor API. The field sensor API, gateway sensor API, and thephysical sensor API can be compatible.

In an optional embodiment, the edge appliance includes: data processing,data storage, deep learning, a user interface, and a field sensor API;wherein the edge appliance generates a virtual sensor data stream fromfield. The virtual sensor network system can further comprise: the edgeappliance capable of providing data to an intelligent gateway using afield sensor API and receiving data from a realtime operations control(ROC) appliance using a ROC API. Optionally the ROC API, field sensorAPI, gateway sensor API, and the physical sensor API are compatible.

In an alternate embodiment, the ROC appliance comprises: dataprocessing, data storage, deep learning, a user interface, and a ROCAPI; wherein the ROC appliance generates a virtual sensor data streamfrom ROC. The ROC appliance can be capable of providing data to an edgeappliance using a ROC API and receiving data from a corporate applianceusing a corporate API. Optionally the virtual sensor network system caninclude compatible API's such as corporate API, ROC API, field sensorAPI, gateway sensor API, and the physical sensor API. Optionally thecorporate appliance includes: data processing, data storage, deeplearning, a user interface, and a corporate API and receiving data froma ROC appliance using a ROC API. The corporate appliance can providedata to a ROC appliance using a corporate API. The intelligent gateway,edge appliance, ROC appliance and corporate appliance can each contain adeep learning model for validation, calibration, signal processing,intelligence, compression, and predictive control. The intelligentgateway, edge appliance, ROC appliance and corporate appliance can eachcontain a command and query responsibility segregation (CQRS) interfacethat enables writing data and receiving data from data storage, queryingdata, and issuing control commands to actuators.

An alternate embodiment is a computer system for establishing a virtualsensor system for managing oilfield activity corresponding to a targetphysical sensor. The computer system includes a database configured tostore information relevant to a virtual sensor process model of thevirtual sensor system and a processor. The processor is configured toselect a plurality of measured parameters provided by a set of physicalsensors based on operational characteristics of the virtual sensorsystem, establish the virtual sensor process model indicative ofinterrelationships between one or more sensing parameter and theplurality of measured parameters, and obtain a set of valuescorresponding to the plurality of measured parameters. It then proceedsto calculate a value of the sensing parameter based upon the set ofvalues corresponding to the plurality of measured parameters and thevirtual sensor process model, and provide the value of the sensingparameter to a control system.

Optionally to select the plurality of measured parameters, the processoris further configured to obtain data records corresponding to aplurality of physical sensors including the set of physical sensors andthe target physical sensor, separate the plurality of physical sensorsinto groups of physical sensors, determine the operationalcharacteristics of the virtual sensor system, and select one or moregroup of physical sensors as the set of physical sensors. In an optionalembodiment to select the one or more group of physical sensors, theprocessor is further configured to determine whether the operationalcharacteristics indicate a closed loop control mechanism, exclude thegroup of physical sensors including the target physical sensor if theoperational characteristics indicate a closed loop control mechanism,and select the group of physical sensors including the target physicalsensor if the operational characteristics do not indicate a closed loopcontrol mechanism.

To establish the virtual sensor process model, the processor can befurther configured to obtain data records associated with one or moreinput variables and the one or more sensing parameter, select theplurality of measured parameters from the one or more input variables,generate a computational model indicative of the interrelationshipsbetween the plurality of measured parameters and the one or more sensingparameter, determine desired statistical distributions of the pluralityof measured parameters of the computational model, and recalibrate theplurality of measured parameters based on the desired statisticaldistributions to define a desired input space. To select the pluralityof measured parameters, the processor may be further configured topre-process the data records, and use a genetic algorithm to select theplurality of measured parameters from the one or more input variablesbased on a Mahalanobis distance between a normal data set and anabnormal data set of the data records. In order to generate acomputational model, the processor may further be configured to create aneural network computational model, train the neural networkcomputational model using the data records, and validate the neuralnetwork computation model using the data records. The computer systemmay be performing real time or near real time analysis.

The input parameter of a virtual sensor may be selected from thenon-limiting group consisting of: pressure, temperature, flowrate, levelindicator, composition indicator, on/off status, actuator position,percent loading, deviation from setpoint, vibration, weight-on-bit,porosity, permeability, resistivity, inclination, direction, sensorreadings from an: acoustic sensor, chemical sensor, density sensor,electrical signal, magnetic sensor, optical sensor, position sensor,pressure sensor, proximity sensor, thermal sensor, vibration sensor, andcombinations thereof. The virtual sensors may each utilize the same APIor alternately each utilize compatible API's.

An alternate embodiment is a method of managing oilfield activity thatincludes: providing an oilfield hosting architecture that comprises aplurality of application shells with application programmable interfacesbetween the application shells, and providing at least one physicalsensor, the physical sensor utilizing a physical sensor applicationprogrammable interface (API). The method further includes providing atleast one intelligent gateway, the intelligent gateway utilizing agateway sensor API, the intelligent gateway receiving data from the atleast one physical sensor, the intelligent gateway comprising at leastone virtual sensor, data processing, data storage and a deep learningagent. The method further includes determining interdependencies andoperational information between the at least one physical sensor andcorresponding at least one virtual sensor, obtaining physical sensordata, using the physical sensor data as input data to the intelligentgateway, generating within the intelligent gateway a virtual sensoroutput data from gateway in response to the physical sensor data, andutilizing the virtual sensor output data from gateway to manage oilfieldactivity. The physical sensor API and gateway sensor API can becompatible. Optionally deep learning can be generated within theintelligent gateway.

The method can further include: providing an edge appliance, the edgeappliance utilizing a field sensor API, the edge appliance receivingdata from the at least one intelligent gateway, the edge appliancecomprising at least one virtual sensor, data processing, data storageand a deep learning agent, using the virtual sensor output data fromgateway as input data to the edge appliance, generating within the edgeappliance a virtual sensor output data from field in response to thevirtual sensor data from gateways, and utilizing the virtual sensoroutput data from field to manage oilfield activity. The field sensor APIand gateway sensor API can be compatible. Optionally deep learning canbe generated within the edge appliance.

In an alternate optional embodiment the method can further includeproviding an ROC appliance, the ROC appliance utilizing a ROC API, theROC appliance receiving data from the edge appliance, the ROC appliancecomprising at least one virtual sensor, data processing, data storageand a deep learning agent, using the virtual sensor output data fromfield as input data to the ROC appliance, generating within the ROCappliance a virtual sensor output data from ROC in response to thevirtual sensor data from fields, and utilizing the virtual sensor outputdata from ROC to manage oilfield activity.

The ROC API and field sensor API can be compatible. The ROC API, fieldsensor API, gateway API, and physical sensor API can be compatible witheach other. Optionally deep learning can be generated within the ROCappliance.

In an alternate optional embodiment the method can further includeproviding a corporate cloud, the corporate cloud utilizing a corporateAPI, the corporate cloud receiving data from the ROC appliance, thecorporate cloud comprising at least one virtual sensor, data processing,data storage and a deep learning agent, using the virtual sensor outputdata from ROC as input data to the corporate cloud, generating withinthe corporate cloud a virtual sensor output data from corporate inresponse to the virtual sensor data from ROC, and utilizing the virtualsensor output data from corporate to manage oilfield activity. Thecorporate API and ROC API can be compatible. The corporate API, ROC API,field sensor API, gateway API, and physical sensor API can be compatiblewith each other. Optionally deep learning can be generated within thecorporate cloud.

In an alternate optional embodiment the method can further includeintegrating a plurality of virtual sensors into a virtual sensornetwork, determining interdependencies among the plurality of virtualsensors, obtaining operational information from the plurality of virtualsensors, and providing one or more virtual sensor output parameters tothe control system based on the determined interdependencies and theoperational information. The method can include determining a firstcondition under which the virtual sensor network is unfit to provide oneor more virtual sensor output parameters to the control system based onthe determined interdependencies and operational information, andpresenting the determined first condition to the control system.

Integrating the plurality of virtual sensors into a virtual sensornetwork can include obtaining data records corresponding to theplurality of virtual sensors, and obtaining model and configurationinformation of the plurality of virtual sensors and optionallycalculating an accuracy value of the virtual sensor network based on thecombination of virtual sensors.

In an alternate optional embodiment the method can further includedetermining whether the accuracy value is desired based on certaincriteria, if it is determined that the accuracy value is not desired,selecting a different combination of model and configuration informationfor the plurality of virtual sensors, and repeating the step ofcalculating the accuracy value and the step of selecting the differentcombination until a desired combination of model and configurationinformation is determined.

Determining the interdependencies can include determining a feedbackrelationship between the output parameter of one virtual sensor from theplurality of virtual sensors and the input parameter of one or more ofother virtual sensors from the plurality of virtual sensors, and storingthe feedback relationship in a table.

Determining the first condition can include monitoring theinterdependencies of the plurality of virtual sensors, and determiningthe occurrence of the first condition when two or more virtual sensorsare both interdependent and providing the sensing data to the controlsystem.

In an alternate optional embodiment the method can further includedetermining a second condition under which an individual virtual sensorfrom the virtual sensor network is unfit to provide the output parameterto the control system, and presenting the determined second condition tothe control system. Determining the second condition can includeobtaining values of the input parameter of a virtual sensor, calculatinga validity metric based on the obtained values, determining whether thecalculated validity metric is within a valid range, and determining thesecond condition if the calculated validity metric is not within thevalid range.

Calculating the validity metric can include evaluating each inputparameter against an established upper and lower bound of the inputparameter, and performing an analysis on a collection of evaluated inputparameter to obtain the validity metric or calculating the Mahalanobisdistance of the input parameter to a valid operating range of thevirtual sensor network.

The method can be performed in real time or near real time analysis. Theinput parameter of a virtual sensor can be selected from the groupconsisting of: pressure, temperature, flowrate, level indicator,composition indicator on/off status, actuator position, percent loading,deviation from setpoint, vibration, acoustic sensor, chemical sensor,density sensor, electrical signal, magnetic sensor, optical sensor,position sensor, pressure sensor, proximity sensor, thermal sensor,vibration sensor, and combinations thereof.

In an embodiment the virtual sensors each utilize the same API orutilize compatible API's. In an alternate optional embodiment the methodcan further include creating a neural network computational model,training the neural network computational model using data records, andvalidating the neural network computation model using the data records.

In an alternate embodiment the present disclosure is a computer systemfor managing oilfield activity that includes an oilfield hostingarchitecture that comprises a plurality of application shells withcompatible application programmable interfaces (API) between theapplication shells; at least one physical sensor, the physical sensorutilizing a physical sensor API; at least one intelligent gatewayappliance utilizing a gateway sensor API, the intelligent gatewayreceiving data from a physical sensor, and generating a virtual sensoroutput data from gateway in response to the physical sensor data, theintelligent gateway comprising a virtual sensor, data processing, datastorage, and a deep learning agent to determine interdependenciesbetween a physical sensor and a corresponding virtual sensor; an edgeappliance, the edge appliance utilizing a field sensor API, the edgeappliance receiving data from an intelligent gateway, and generatingwithin the edge appliance a virtual sensor output data from field inresponse to the virtual sensor data from gateway, the edge appliancecomprising a virtual sensor, data processing, data storage and a deeplearning agent; a ROC appliance, the ROC appliance utilizing a ROC API,the ROC appliance receiving data from the edge appliance, and generatingwithin the ROC appliance a virtual sensor output data from ROC inresponse to the virtual sensor data from field, the ROC appliancecomprising at least one virtual sensor, data processing, data storageand a deep learning agent; and a corporate appliance, the corporateappliance utilizing a corporate API, the corporate appliance receivingdata from the ROC appliance, generating within the corporate appliance avirtual sensor output data from corporate in response to the virtualsensor data from ROC, the corporate appliance comprising a virtualsensor, data processing, data storage and a deep learning agent.

The physical sensor API, gateway sensor API, field sensor API, ROC API,and corporate API can each be compatible with each other. The virtualsensor output data from gateway, virtual sensor output data from field,virtual sensor output data from ROC, and virtual sensor output data fromcorporate can be used to manage oilfield activity.

In an embodiment a plurality of the physical sensors are configured intoa virtual sensor network, and the computer system can obtain datarecords associated with physical sensors, generate a computational modelindicative of the interrelationships between physical sensor data andvirtual sensor data, train the computational model using the datarecords, and validate the computation model using the data records. Thecomputer system can be capable of real time or near real time analysis.

The physical sensor data can be selected from the illustrative andnon-limiting group consisting of: pressure, temperature, flowrate, levelindicator, composition indicator, on/off status, actuator position,percent loading, deviation from setpoint, vibration, weight-on-bit,porosity, permeability, resistivity, inclination, direction, drillingmud data, LWD data, MWD data, and/or sensor readings from an: acousticsensor, chemical sensor, density sensor, electrical signal, magneticsensor, optical sensor, position sensor, pressure sensor, proximitysensor, thermal sensor, vibration sensor, and combinations thereof.

An input to an intelligent edge appliance can be selected from theillustrative and non-limiting group consisting of: the capacity offacilities to produce, collect, process, store, and transport theproduction from the wells; local weather information; transportationlimitations on moving rigs and equipment; transportation limitations ongas and oil pipelines and railcar traffic; facility design includingengineering design, detailed design, construction, transportation,installation, conformance testing; and combinations thereof.

An input to a ROC appliance can be selected from the illustrative andnon-limiting group consisting of: the stability of local and regionalweather conditions; the size and capacity of processing facilities;amount of oil and/or gas reserves in a field; the shape and physicalproperties of reservoirs in each field; reservoir modeling; the amountof time it will take to drill each exploratory well and each productionwell; the availability of equipment such as drilling rigs, drill pipe,casing, tubing and completion rigs; transportation limitations; thecosts associated with operating and maintaining production from thewells and related facilities; the costs associated with operating andmaintaining injection wells and related facilities; optimized productionrates from the reservoir; reservoir decline profiles; optimizedproduction rates from the field; in cases with a plurality of potentialproductive assets, which assets, and which order to develop and producethe assets; and combinations thereof.

An input to a corporate appliance can be selected from the illustrativeand non-limiting group consisting of: the future prices of oil and gas;tax rates; royalty rates; profit-sharing percentages; ownershippercentages (e.g., equity interests); basin modeling; reservoirmodeling; seismic data; leased land holdings; regional climateconsiderations; and combinations thereof

The text above describes one or more specific embodiments of a broaderdisclosure. The disclosure also is carried out in a variety of alternateembodiments and thus is not limited to those described here. Theforegoing description of an embodiment of the disclosure has beenpresented for the purposes of illustration and description. It is notintended to be exhaustive or to limit the disclosure to the precise formdisclosed herein. Many modifications and variations are possible inlight of the above teaching. It is intended that the scope of thedisclosure be limited not by this detailed description, but rather bythe claims appended hereto.

1. A method of operating an oilfield device comprising: providing aphysical sensor; providing a virtual sensor; establishinginterdependencies between the physical sensor and virtual sensor;obtaining a physical sensor data stream relating to an oilfield device;using the physical sensor data stream as input data to the virtualsensor; generating a virtual sensor output data stream; and using thevirtual sensor output data stream to control the oilfield device.
 2. Themethod of claim 1, further comprising: determining whether the physicalsensor data stream is reliable.
 3. The method of claim 1, furthercomprising: determining whether the physical sensor data stream iswithin a predetermined acceptable range.
 4. The method of claim 1,wherein the physical sensor is selected from the group consisting of:acoustic sensor, chemical sensor, density sensor, electrical sensor,flow sensor, hydraulic sensor, level sensor, magnetic sensor, mechanicalsensor, optical sensor, position sensor, pressure sensor, proximitysensor, thermal sensor, vibration sensor, and combinations thereof. 5.The method of claim 1, further comprising: using the physical sensordata stream as input data to the virtual sensor utilizing a physicalsensor application programmable interface (API); and sending the virtualsensor data stream to a control system utilizing an API that iscompatible with the physical sensor API.
 6. The method of claim 1,further comprising: linking the virtual sensor with other virtualsensors to form a virtual sensor network.
 7. The method of claim 6,further comprising: obtaining virtual sensor model information;determining interdependencies among virtual sensor models; monitoringand controlling individual virtual sensor models; and monitoring andcontrolling the virtual sensor network.
 8. The method of claim 5,wherein the virtual sensor is an intelligent gateway that includes dataprocessing, data storage, deep learning, a user interface, and a gatewaysensor API; the method further comprising: generating a virtual sensordata stream from gateway.
 9. The method of claim 8, further comprising:the intelligent gateway exchanging data with a physical sensor using thephysical sensor API and receiving data from an edge appliance using afield sensor API.
 10. The method of claim 9, wherein the field sensorAPI, gateway sensor API, and the physical sensor API are compatible. 11.The method of claim 9, further comprising: using the virtual sensor datastream from gateway as input data to the edge appliance utilizing thegateway sensor API; analyzing the virtual sensor data stream fromgateway within the edge appliance, the edge appliance comprising dataprocessing, data storage, deep learning, a user interface, and afieldsensor API; the method further comprising: generating a virtual sensordata stream from field.
 12. The method of claim 11, farther comprising:the edge appliance providing data to the intelligent gateway using thefield sensor API and receiving data from a realtime operations control(ROC) appliance using a ROC API.
 13. The method of claim 12, wherein theROC API, field sensor API, gateway sensor API, and the physical sensorAPI are compatible.
 14. The method of claim 12, further comprising:using the virtual sensor data stream from field as input data to a ROCappliance utilizing the field sensor API; analyzing the virtual sensordata stream from field within the ROC appliance, the ROC appliancecomprising data processing, data storage, deep learning, a userinterface, and a ROC API; the method further comprising: generating avirtual sensor data stream from ROC.
 15. The method of claim 14, furthercomprising: the ROC appliance providing data to an edge appliance usingthe ROC API and receiving data from a corporate appliance using acorporate API.
 16. The method of claim 15, wherein the corporate API,ROC API, field sensor API, gateway sensor API, and the physical sensorAPI are compatible with each other.
 17. The method of claim 15, furthercomprising: using the virtual sensor data stream from ROC as input datato a corporate appliance utilizing a ROC API; analyzing the virtualsensor data stream from ROC within the corporate appliance, thecorporate appliance comprising data processing, data storage, deeplearning, a user interface, and a corporate API.
 18. The method of claim17, wherein the intelligent gateway, edge appliance, ROC appliance andcorporate appliance each contain a deep learning model for validation,calibration, signal processing, intelligence, compression, andpredictive control.
 19. The method of claim 17, wherein the intelligentgateway, edge appliance, ROC appliance and corporate appliance eachcontain a command, and query responsibility segregation (CQRS) interfacethat enables writing data and receiving data from data storage, queryingdata, and issuing control commands to actuators.
 20. A virtual sensornetwork system for managing oilfield activity with a control systemcomprising: a plurality of virtual sensors, each having a model type, atleast one input parameter, and at least one output parameter, integratedinto a virtual sensor network; an input interface to obtain data fromcorresponding physical sensors; an output interface to provide data to acontrol system; and a controller configured to: determineinterdependencies among the plurality of virtual sensors; obtainoperational information of the plurality of virtual sensors; and provideone or more virtual sensor output parameters to the control system basedon the determined interdependencies and the operational information.21-88. (canceled)